In the related art, for example, a battery module formed by arranging a plurality of battery cells such as lithium ion secondary batteries or the like is known. In such a battery module, by enclosing an array body of battery cells by a retaining tool such as a metal plate or the like to be restricted with a constant load, variation in properties such as internal resistance or the like in the battery cells is suppressed. For example, in a battery pack disclosed in Patent Literature 1, a metal band having bent portions at both ends thereof is fixed to an end plate, and a battery block is restricted by the end plate in a stacking direction. In such a battery module, in order to prevent damage to a retaining member due to expansion of the battery cells, an elastic body such as rubber or the like may be interposed between the array body and an end plate of the retaining member.
In addition, a harness used for detection of a voltage or the like of each of the battery cells is assembled to the battery module. For example, in the battery pack disclosed in Patent Literature 2, by holding connectors including voltage detection terminals by a holding member and attaching the holding member to a battery group, the connectors are collectively electrically connected to electrode terminals of the battery cells.